Do breast tumors often metastasize to local lymph nodes?

Yes: App. 1 in 3 women diagnosed with breast cancer will have evidence of cancer spread to the lymph nodes in the armpit on the affected side. This indicates the high probability of cancer cells "elsewhere" in the body but does not mean that the cancer is incurable. This usually warrants the recommendation for chemotherapy to kill these "elsewheres"; thankfully, this is often successful.